[Nexus 7 (2013) Q&A] Dazmatic:
C:\Users\Nigel>fastboot oem gpt-info
...
(bootloader) partition[1].name = radio
(bootloader) partition[1].first_lba = 131072
(bootloader) partition[1].last_lba = 306143
(bootloader) partition[1].size 87536 KB
(bootloader) partition[2].name = modemst1
(bootloader) partition[2].first_lba = 393216
(bootloader) partition[2].last_lba = 399359
(bootloader) partition[2].size 3072 KB
(bootloader) partition[3].name = modemst2
(bootloader) partition[3].first_lba = 399360
(bootloader) partition[3].last_lba = 405503
(bootloader) partition[3].size 3072 KB
(bootloader) partition[4].name = persist
(bootloader) partition[4].first_lba = 524288
(bootloader) partition[4].last_lba = 554287
(bootloader) partition[4].size 15000 KB
(bootloader) partition[5].name = m9kefs1
(bootloader) partition[5].first_lba = 655360
(bootloader) partition[5].last_lba = 656919
(bootloader) partition[5].size 780 KB
(bootloader) partition[6].name = m9kefs2
(bootloader) partition[6].first_lba = 656920
(bootloader) partition[6].last_lba = 658479
(bootloader) partition[6].size 780 KB
(bootloader) partition[7].name = m9kefs3
(bootloader) partition[7].first_lba = 786432
(bootloader) partition[7].last_lba = 787991
(bootloader) partition[7].size 780 KB
(bootloader) partition[8].name = fsg
(bootloader) partition[8].first_lba = 787992
(bootloader) partition[8].last_lba = 794135
(bootloader) partition[8].size 3072 KB
(bootloader) partition[9].name = sbl1
(bootloader) partition[9].first_lba = 917504
(bootloader) partition[9].last_lba = 920503
(bootloader) partition[9].size 1500 KB
(bootloader) partition[10].name = sbl2
(bootloader) partition[10].first_lba = 920504
(bootloader) partition[10].last_lba = 923503
(bootloader) partition[10].size 1500 KB
(bootloader) partition[11].name = sbl3
(bootloader) partition[11].first_lba = 923504
(bootloader) partition[11].last_lba = 927599
(bootloader) partition[11].size 2048 KB
(bootloader) partition[12].name = aboot
(bootloader) partition[12].first_lba = 927600
(bootloader) partition[12].last_lba = 937839
(bootloader) partition[12].size 5120 KB
(bootloader) partition[13].name = rpm
(bootloader) partition[13].first_lba = 937840
(bootloader) partition[13].last_lba = 938863
(bootloader) partition[13].size 512 KB
(bootloader) partition[14].name = boot
(bootloader) partition[14].first_lba = 1048576
(bootloader) partition[14].last_lba = 1081343
(bootloader) partition[14].size 16384 KB
(bootloader) partition[15].name = tz
(bootloader) partition[15].first_lba = 1179648
(bootloader) partition[15].last_lba = 1180671
(bootloader) partition[15].size 512 KB
(bootloader) partition[16].name = pad
(bootloader) partition[16].first_lba = 1180672
(bootloader) partition[16].last_lba = 1180673
(bootloader) partition[16].size 1 KB
(bootloader) partition[17].name = sbl2b
(bootloader) partition[17].first_lba = 1180674
(bootloader) partition[17].last_lba = 1183673
(bootloader) partition[17].size 1500 KB
(bootloader) partition[18].name = sbl3b
(bootloader) partition[18].first_lba = 1183674
(bootloader) partition[18].last_lba = 1187769
(bootloader) partition[18].size 2048 KB
(bootloader) partition[19].name = abootb
(bootloader) partition[19].first_lba = 1187770
(bootloader) partition[19].last_lba = 1198009
(bootloader) partition[19].size 5120 KB
(bootloader) partition[20].name = rpmb
(bootloader) partition[20].first_lba = 1198010
(bootloader) partition[20].last_lba = 1199033
(bootloader) partition[20].size 512 KB
(bootloader) partition[21].name = tzb
(bootloader) partition[21].first_lba = 1199034
(bootloader) partition[21].last_lba = 1200057
(bootloader) partition[21].size 512 KB
(bootloader) partition[22].name = system
(bootloader) partition[22].first_lba = 1310720
(bootloader) partition[22].last_lba = 3031039
(bootloader) partition[22].size 860160 KB
(bootloader) partition[23].name = cache
(bootloader) partition[23].first_lba = 3031040
(bootloader) partition[23].last_lba = 4177919
(bootloader) partition[23].size 573440 KB
(bootloader) partition[24].name = misc
(bootloader) partition[24].first_lba = 4194304
(bootloader) partition[24].last_lba = 4196351
(bootloader) partition[24].size 1024 KB
(bootloader) partition[25].name = recovery
(bootloader) partition[25].first_lba = 4325376
(bootloader) partition[25].last_lba = 4345855
(bootloader) partition[25].size 10240 KB
(bootloader) partition[26].name = DDR
(bootloader) partition[26].first_lba = 4456448
(bootloader) partition[26].last_lba = 4456463
(bootloader) partition[26].size 8 KB
(bootloader) partition[27].name = ssd
(bootloader) partition[27].first_lba = 4456464
(bootloader) partition[27].last_lba = 4456479
(bootloader) partition[27].size 8 KB
(bootloader) partition[28].name = m9kefsc
(bootloader) partition[28].first_lba = 4456480
(bootloader) partition[28].last_lba = 4456481
(bootloader) partition[28].size 1 KB
(bootloader) partition[29].name = metadata
(bootloader) partition[29].first_lba = 4587520
(bootloader) partition[29].last_lba = 4587583
(bootloader) partition[29].size 32 KB
(bootloader) partition[30].name = userdata
(bootloader) partition[30].first_lba = 4718592
(bootloader) partition[30].last_lba = 60424158
(bootloader) partition[30].size 27852783 KB
(bootloader) partition[31].name =
(bootloader) partition[31].first_lba = 0
(bootloader) partition[31].last_lba = 0
(bootloader) partition[31].size 0 KB
(bootloader) partition[32].name =
(bootloader) partition[32].first_lba = 0
(bootloader) partition[32].last_lba = 0
(bootloader) partition[32].size 0 KB
(bootloader) partition[33].name =
(bootloader) partition[33].first_lba = 0
(bootloader) partition[33].last_lba = 0
(bootloader) partition[33].size 0 KB
(bootloader) partition[34].name =
(bootloader) partition[34].first_lba = 0
(bootloader) partition[34].last_lba = 0
(bootloader) partition[34].size 0 KB
(bootloader) partition[35].name =
(bootloader) partition[35].first_lba = 0
(bootloader) partition[35].last_lba = 0
(bootloader) partition[35].size 0 KB
(bootloader) partition[36].name =
(bootloader) partition[36].first_lba = 0
(bootloader) partition[36].last_lba = 0
(bootloader) partition[36].size 0 KB
(bootloader) partition[37].name =
(bootloader) partition[37].first_lba = 0
(bootloader) partition[37].last_lba = 0
(bootloader) partition[37].size 0 KB
OKAY [ 0.451s]
finished. total time: 0.451s

with the format cache, it just sits there at erasing, that much is certain.

I can get the device into 9008/6 mode although it doesn't appear to be very responsive. However, in 9006 mode it appears as a qualcomm USB device. windows refuses to see the drive however HDD Raw copy tool lets me see the device.

I've even tried using HDD Raw copy to read the flash but I just get errors saying "the semaphore timeout period has expired"

I have just bought a 16gb Nexus 7 motherboard so I'm going to fit that for now. However, I'm half tempted with the USB EMMC adapter as that's a feasible repair.

I don't know what 32gb emmc chip to use though? I know I can get a kingston 16gb chip for ~£5 on ebay but I'd need an image to use to write to it and that's a whole other affair, getting the image written to the chip correctly with the correct partition tables and such.